The 3-Lug Mount is a quick-attach mounting option for guns with fixed barrels. It is compatible with the following SilencerCo suppressors: Octane series Omega 9K Omega 45K Hybrid 46 Hybrid 46M (Requires AC4751) Omega 36M (Requires AC4751) The 3-Lug Mount must be used with a 3-Lug Muzzle Device. The 45 caliber 3-Lug Mount must be used only with 45 caliber 3-Lug Mount Muzzle Devices; the 9mm must only be used with 9mm 3-Lug Devices. SKUS 9MM (AC2447) 45 (AC2448) The 45 caliber 3-Lug Mounts are made to B&T Spec. Mfg: Silencerco